This invention relates to an electric refrigerator equipped with an automatic ice-making unit.
Heretofore, a refrigerator has been proposed in which a refrigerating chamber is combined with various types of ice-making units such as an atmospheric type which produces ice in an ice making unit arranged in a freezing chamber under the low temperature atmosphere of the freezing chamber provided for the refrigerator, or a circulation type which produces ice by supplying the water to an ice-making plate maintained at a low temperature to form ice with subsequent heating of the plate for removing the ice. To obtain a desired amount of the ice, however, the former type requires an extremely long time for ice-making due to poor cooling efficiency while the latter type requires the ice-removing operation, resulting in a substantially long time for one cycle of the ice-making with limitation in an ice-making capacity per day. Therefore, the refrigerator equipped with the conventional ice-making unit is disadvantageous for business use requiring a high ice-making capacity.
Further, in the known refrigerator equipped with the conventional ice-making unit, the ice produced in the ice-making unit is stored in the ice-storing chamber communicating with the refrigerating chamber so that the cold air in the ice-storing chamber is introduced into the refrigerating chamber. In the refrigerator of this type, the ice-storing chamber must be arranged above the refrigerating chamber in order to increase the cooling efficiency. As a result, the ice-making unit must be also positioned above the refrigerating chamber, resulting in enlargement of the refrigerator with less stability and inconvenience in maintenance and inspection of the ice-making unit.
After intensive studies, the inventors have found that the most preferred ice-making unit to be combined with the refrigerator is an auger type ice-making unit which is compact in structure and permits a continuous production of the ice and a transportation of the ice in any desired direction. The auger type ice-making unit usually comprises a cooling cylinder opened at its upper end and provided at its outer periphery with an evaporator, a water supply pipe communicating with a bottom of the cooling cylinder, an auger rotatably mounted in the cooling cylinder to scrape off a thin ice layer formed on an inner peripheral surface of the cooling cylinder with upward transfer of the scraped ice, and a driving means for turning the auger. It has been confirmed that utilization of the auger type ice-making unit brings the following advantages:
a. Since the ice-removing operation is ommited, the ice-making capacity has been extremely increased. PA1 b. Since the ice produced in the ice-making unit is transferred very conveniently, the ice-storing chamber may be arranged at the uppermost place or any desired place in the refrigerator. PA1 c. The refrigerating chamber may also be positioned at the most convenient location of the refrigerator with a sufficient volume.
In the auger type ice-making unit, an ice compression die is provided at an upper end of the cooling cylinder to compress the scraped ice into ice masses, and the resultant ice masses are smoothly and continuously transferred to the desired place through a flexible tube, hence the location of the ice-making unit may be optionally selected.
Thus, it has also been found that with utilization of the auger type ice-making unit the cooling unit and the ice-making unit may be arranged together at the bottom of the refrigerator and the refrigeration system serving for the both units may be operated by a common compressor which enables simplification of the controlling system and compactness of the apparatus with less production cost as well as electricity consumption.
In order to employ a common compressor operable for both the cooling unit and the auger type automatic ice-making unit, a cooling evaporator of the auger type ice-making unit is connected in parallel to an evaporator of the cooling unit and the change-over valves for refrigerant are connected to the inlets of the respective evaporators. The change-over valve connected to the evaporator of the cooling unit is controlled by a temperature sensitive element arranged in the refrigerating chamber while the other change-over valve connected to the cooling evaporator of the auger type automatic ice-making unit is controlled by an ice detecting switch arranged in the ice-storing chamber. Thus, it has been found that the refrigeration of the refrigerating chamber and the supply of the ice into the ice-storing chamber may be separately and smoothly controlled.